Saturation control of electric machine

Abstract

The invention includes an electric alternator/motor having a rotor, stator and at least one winding in the stator adapted to conduct a current, the machine also having and first and second magnetic circuits, one of which includes a saturable portion in which saturation may be controlled to permit control of the machine.

What is claimed is: 
     
       1. A method of regulating operation of an electrical machine, the method involving a plurality of electric machines, each machine having a magnetic rotor, a stator and at least one stator winding, the winding associated with a primary magnetic circuit defined by the rotor and stator, the winding also associated with a secondary magnetic circuit defined in the stator, the secondary magnetic circuit remote from the first magnetic circuit and including a magnetically saturable portion, the method comprising the steps of:
 operating each machine to provide at least one of generated output electrical power in the winding and motive power as a result of current supplied to the winding; 
 controllably varying a saturation level of a portion of the secondary magnetic circuit to thereby control operation of each machine; 
 monitoring the output of each machine for at least one criterion indicative of a fault condition existing in a deficient machine resulting in an associated power decrease; 
 controllably varying a saturation level of at least one non-deficient machine to compensate for said power decrease. 
 
     
     
       2. The method of  claim 1 , wherein said associated power decrease is due to at least one of a failure and shut down of the deficient machine. 
     
     
       3. The method of  claim 1 , wherein in at least one of the machines, the stator comprises a first stator portion and a second stator portion, and wherein the magnetic rotor rotates adjacent the first stator portion and the saturation level is controlled adjacent the second stator portion. 
     
     
       4. The method of  claim 3 , wherein the first and second stator portions are disposed axially beside one another relative to a common axis of the stator portions. 
     
     
       5. The method of  claim 3 , wherein the stator portions are distinct components relative to one another. 
     
     
       6. The method of  claim 1 , wherein the step of controllably varying the saturation level includes providing electric power from a power source to an electromagnetic saturation assembly. 
     
     
       7. The method of  claim 1 , wherein the magnetic rotor of each machine includes at least one permanent magnet.